Britain spied on Argentine military and political leaders to ensure the security of the Falkland Islands from 2006 to 2011, an Argentine television channel reported on Friday, citing intelligence documents provided by Edward J. Snowden, the former National Security Agency contractor.

Channel TN said it got the documents from a team of reporters in Brazil who have been working with Mr. Snowden. One of the documents, labeled “top secret” and dated 2010, described “efforts to collect high-priority military and leadership communications,” the channel said. Tensions over the Falklands still simmer more than 30 years after the two countries fought a brief war, won by Britain, for control of the South Atlantic archipelago. Oil has been discovered in the area, raising the stakes in the dispute over control of the islands. A spokesman for Britain’s Foreign Office said the government would neither confirm nor deny the reports. No one from the Argentine government was available to comment.